This application is based on and claims priority to Japanese Patent Application No. 2001-136928, filed on May 8, 2001, the entire content of which is hereby incorporated by reference.
1. Field of the Invention
The present invention relates generally to a braking device for a watercraft.
2. Description of Related Art
Relatively small watercrafts such as, for example, personal watercrafts have become very popular in recent years. This type of watercraft is quite sporting in nature and carries one or more riders. A hull of the watercraft typically defines a rider""s area above an engine compartment. An internal combustion engine powers a jet propulsion unit that propels the watercraft by discharging water rearwardly. The engine lies within the engine compartment in front of a tunnel or gullet that is formed on an underside of the hull. The jet propulsion unit is placed within the tunnel and includes an impeller that is driven by the engine. The jet propulsion unit includes a discharge nozzle through which water is jetted and a deflector or steering nozzle disposed at an end of the nozzle to change a direction of the water jet.
A steering column is disposed at the front of the rider""s area. The steering column typically is connected to a handle bar on which a throttle lever is provided. The handle bar is connected to the steering nozzle. The rider operates the throttle lever to control the power of the engine and thus the speed of the watercraft. The rider also can steer the handle bar to rotate the steering nozzle so as to change the direction of the watercraft""s travel.
It has been previously proposed to employ a braking device to assist in slowing down the watercraft. For instance, Japanese Laid Open Publication No. H02-254096 discloses an exemplary braking device. That braking device includes a baffle plate to baffle water from flowing smoothly along a bottom surface of the hull. The baffle plate is normally housed in a recessed portion of the hull. When the rider steps on a pedal, the baffle protrudes below the bottom surface of the hull. In the lowered position, however, the baffle is susceptible to damage as the baffle can strike underwater or floating objects such as, for example, driftwood.
The present invention relates to an improved braking device that can be selectively operated to assist in slowing the watercraft when desired, such as, when docking the watercraft. In a preferred mode, the braking device does not protrude below the bottom of the watercraft hull by any significant degree, thus reducing the possibility of damage caused by underwater or floating objects over which the watercraft may travel when braking.
One aspect of the present invention thus involves a resistance creating device that is employed on a watercraft and is selectively operated to slow the watercraft when desired. The watercraft comprises a hull having a bottom surface and a propulsion unit. When the propulsion unit propels the watercraft, water flows along the bottom surface of the hull as the watercraft travels across the water surface. The resistance creating device comprises a first member and a second member. The first member is movable between first and second positions and is arranged to impede at least a portion of the water flowing along the bottom surface of the hull when in the first position; however, when in the second position, the first member does not significantly impede water flow along the bottom surface of the hull. The second member also is movable between its own first and second positions. The second member is arranged such that, when the second member is in the first position, the second member directs the portion of water toward the first member in its first position. The second member is also arranged such that, when the second member is in the second position, the second member does not significantly alter the water flow along the bottom surface of the hull.
In accordance with another aspect of the present invention, a watercraft comprises a hull having a bottom surface, a jet propulsion unit configured to generate a water jet for propelling the hull, and an auxiliary unit affixed to the hull. The jet propulsion unit is disposed at a rear end of the hull and includes a discharge nozzle and a steering nozzle. The steering nozzle receives the water jet from discharge nozzle. The auxiliary unit defines a bottom surface that extends below at least a portion of at least one of the nozzles and is generally contiguous to the hull bottom surface. A brake is hinged onto the auxiliary unit for pivotal movement and is movable between a non-braking position and a fully braking position. The brake impedes water flow under the hull at least when placed in the fully braking position. A water guide also is hinged onto the auxiliary unit for pivotal movement. The water guide is movable between a non-guiding position and a fully guiding position. The water guide has a bottom surface that extends generally contiguously from at least a portion of the bottom surface of the auxiliary unit while placed in the non-guiding position. The water guide is also arranged to guide water flowing along the bottom surface of the auxiliary unit toward the brake at least when placed in the fully guiding position.